1. Field of the Invention
The present invention relates to a semiconductor device having a resonance circuit. The present invention also relates to a semiconductor device capable of transmitting and receiving data by wireless communication.
2. Description of the Related Art
In recent years, an environment where information network can be accessed at any time in any situations, which is referred to as a ubiquitous information society, has been facilitated. In such an environment, individual recognition technology has attracted attention. For example, there is technology that can be used for production, management, and the like, in which a history of an object is clarified by giving an ID (an individual recognition code) to an individual object. Above all, a semiconductor device capable of transmitting and receiving data by wireless communication is beginning to be utilized
In a semiconductor device of a transmitter/receiver, which can, for example, record and erase data by transmitting and receiving data without contact, antennas are arranged and resonance frequency is determined in advance so that an electromagnetic wave is made to intervene between this semiconductor device having a structure in which integrated circuits are mounted on the antenna and a reader/writer device to be able to transmit and receive data.
Conventionally, in order to obtain the predetermined resonance frequency, in a semiconductor device, capacitance is provided by stacking a plurality of plate-shaped conductors over a main body of an antenna over the semiconductor device through an insulator. An end of one conductive line of which another end is connected to the plurality of the plate-shaped conductors, is connected to the main body of the antenna of the semiconductor device. A leading portion, to which the plurality of the plate-shaped conductors of the conductive line is connected, is provided in a portion not in a perpendicular direction, which extends from the main body of the antenna of the semiconductor device and is not overlapped or underlapped with the main body of the antenna. The leading portion of the conductive line is divided to adjust the capacitance, and then, the predetermined resonance frequency is obtained (for example, see Patent document 1; Japanese Patent Application Laid-Open No. 2002-246829).